<?php
// +----------------------------------------------------------------------
// | JIANKE [ WWW.XYSER.COM ]
// +----------------------------------------------------------------------
// | Copyright (c) 2015 http://xyser.com All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( dingdayu )
// +----------------------------------------------------------------------
// | Author: dingdayu <614422099@qq.com>
// +----------------------------------------------------------------------
// | DATE: 2015-11-4 2:15
// +----------------------------------------------------------------------

/**
 * 字符串截取，支持中文和其他编码
 * @static
 * @access public
 * @param string $str 需要转换的字符串
 * @param string $start 开始位置
 * @param string $length 截取长度
 * @param string $charset 编码格式
 * @param string $suffix 截断显示字符
 * @return string
 */
function msubstr($str, $start=0, $length, $charset="utf-8", $suffix=true) {
    if(function_exists("mb_substr"))
        $slice = mb_substr($str, $start, $length, $charset);
    elseif(function_exists('iconv_substr')) {
        $slice = iconv_substr($str,$start,$length,$charset);
        if(false === $slice) {
            $slice = '';
        }
    }else{
        $re['utf-8']   = "/[\x01-\x7f]|[\xc2-\xdf][\x80-\xbf]|[\xe0-\xef][\x80-\xbf]{2}|[\xf0-\xff][\x80-\xbf]{3}/";
        $re['gb2312'] = "/[\x01-\x7f]|[\xb0-\xf7][\xa0-\xfe]/";
        $re['gbk']    = "/[\x01-\x7f]|[\x81-\xfe][\x40-\xfe]/";
        $re['big5']   = "/[\x01-\x7f]|[\x81-\xfe]([\x40-\x7e]|\xa1-\xfe])/";
        preg_match_all($re[$charset], $str, $match);
        $slice = join("",array_slice($match[0], $start, $length));
    }
    $suffix = (iconv_strlen($slice,$charset) > $length && $suffix);
    return $suffix ? $slice.'...' : $slice;
}

function array_depth($array) {
    if(!is_array($array)) return 0;
    $max_depth = 1;
    foreach ($array as $value) {
        if (is_array($value)) {
            $depth = array_depth($value) + 1;

            if ($depth > $max_depth) {
                $max_depth = $depth;
            }
        }
    }
    return $max_depth;
}

/**
 *自动判断把gbk或gb2312编码的字符串转为utf8
 *能自动判断输入字符串的编码类，如果本身是utf-8就不用转换，否则就转换为utf-8的字符串
 *支持的字符编码类型是：utf-8,gbk,gb2312
 *@$str:string 字符串
 */
function gbk2utf8($str){
    $charset = mb_detect_encoding($str,array('UTF-8','GBK','GB2312'));
    $charset = strtolower($charset);
    if('cp936' == $charset){
        $charset='GBK';
    }
    if("utf-8" != $charset){
        $str = iconv($charset,"UTF-8//IGNORE",$str);
    }
    return $str;
}